The present invention relates to the art of pre-press proofing, and in particular, to a method of preparing high quality transparencies using a method similar to that which is used to create pre-press proofs, such as by the use of pressure and heat to laminate media together.
Pre-press proofing is a procedure that is used primarily by the printing industry for creating representative images of printed material. In the printing industry pre-press proofs are used to check for color balance, control parameters and other important image quality requirements, without the cost and time that is required to actually produce printing plates, set up a printing press and produce an example of an representative image, which would result in higher costs and a loss of profits that would ultimately be passed on to the customer.
To create a pre-press proof, first an original image is separated into individual color separations or digital files. The original image is scanned and separated into the three subtractive primaries and black. Typically, a color scanner is used to create the color separations or digital files and in some instances more than four, color separations or digital files are used. Although there are several ways used in the printing industry to create a pre-press proof from the color separations or digital files they are generally one of three types. The first method involves a color overlay system that employs the representative image on a separate base for each color, which is then overlaid to create a pre-press proof. The second method involves a single integral sheet process in which the separate colors for the representative image are transferred one at a time by lamination onto a single base, and a third method involves a digital method in which the representative image is produced directly onto a receiver stock, or onto an intermediate sheet then transferred by lamination onto a receiver stock from digital files.
The representative image to be laminated can be, but is not limited to, being created on a commercially available Kodak image processing apparatus, depicted in commonly assigned U.S. Pat. No. 5,268,708 which describes an image processing apparatus having half-tone color imaging capabilities. The above-mentioned image processing apparatus is arranged to form a representative image onto a sheet of thermal print media. Dye from a sheet of dye donor material is transferred to the thermal print media, by applying a sufficient amount of thermal energy to the dye donor sheet material to form the representative image. The image processing apparatus is comprised generally of a material supply assembly, which includes a lathe bed scanning subsystem. The scanning subsystem includes: a lathe bed scanning frame, translation drive, translation stage member, printhead, imaging drum and media exit transports.
The operation of the image processing apparatus comprises: metering a length of the thermal print media (in roll form) from the material supply assembly. The thermal print media is then measured and cut into sheet form of the required length and transported to the imaging drum, registered, wrapped around and secured onto the imaging drum. Next, a length of dye donor material (in roll form) is also metered out of the material supply assembly, then measured and cut into sheet form of the required length. The material is then transported to the imaging drum, wrapped around the imaging drum utilizing a load roller which is described in detail, in commonly assigned U.S. Pat. No. 5,268,708, such that it is superposed into the desired registration with respect to the thermal print media (which has already been secured to the imaging drum).
After the dye donor sheet material is secured to the periphery of the imaging drum, the scanning subsystem or write engine provides the imaging function. This imaging function is accomplished by retaining the thermal print media and the dye donor sheet material on the imaging drum while it is rotated past the printhead. The translation drive traverses the printhead and translation stage member axially along the axis of the imaging drum, in coordinated motion with the rotating imaging drum. These movements combine to produce the representative image on the thermal print media.
Once a representative image has been formed on the thermal print media, the dye donor sheet material is then removed from the imaging drum. This is accomplished without disturbing the thermal print media that is beneath it. The dye donor sheet material is then transported out of the image processing apparatus by means of the material exit transport. Additional dye donor sheet materials are sequentially superimposed with the thermal print media on the imaging drum, and then imaged onto the thermal print media as previously mentioned, until the representative image is completed onto the thermal print media. The completed representative image formed thereon is then unloaded from the imaging drum and transported by the receiver sheet material exit transport to an exit tray in the exterior of the image processing apparatus.
After a representative image has been formed on the thermal print media as previously described, it is then transferred to the receiver stock such that the pre-press proof is representative of an image that would be printed on a printing press. A Kodak Laminator as described in U.S. Pat. No. 5,478,434 can be used to bond or laminate the representative image as a part of a color proofing system, but bonding is not limited to such a device. U.S. Pat. No. 5,203,942 describes a Kodak Laminator that employs a lamination/de-lamination system as applied to a drum laminator and pending U.S. patent application Ser. No. 09/676,877, now U.S. Pat. No. 6,463,981 describes a Kodak Laminator that employs endless belts incorporated into the lamination apparatus. For the purpose of this patent application the laminator described in pending U.S. patent application Ser. No. 09/676,877, now U.S. Pat. No. 6,463,981, will be used. It should be noted that the present invention described in this disclosure is not limited to a Kodak Laminator or type of laminator referenced above.
Generally laminating a pre-press proof is a two-pass process. For the first step, a sheet of pre-laminate, which has a pre-laminate support layer and an encapsulation or protective layer, is placed on top of a receiver sheet, which is also called xe2x80x9creceiver stockxe2x80x9d in the industry. This construction of multiple layers is a lamination sandwich, which is fed into the laminator. Once the lamination sandwich exits the laminator the pre-laminate support layer is peeled away from the now pre-laminated receiver stock.
For the second pass, the imaged thermal print media with the representative image formed thereon is placed on the pre-laminated receiver stock with representative image face down on the pre-laminated receiver stock and fed into the laminator. After the lamination sandwich has exited the laminator, the thermal print support layer is peeled away, leaving the completed pre-press proof simulating an image produced on a printing press.
Though the above-described lamination method works well for both laser thermal ink jet pre-press proofs, there exists a need for high quality transparences.
The present invention provides a method for producing high quality transparences. Specifically, the invention involves laminating a transparency consisting of the steps of: creating an imaged receiver sheet having an image, a first thermal print layer, and a first support layer; consisting of a first support base, first aluminized layer, and a first release layer. Laminating the imaged receiver sheet to an imageless receiver sheet with a second thermal print layer and a second support layer; consisting of a second support base, second aluminized layer, and a second release layer, thereby encapsulating the image; removing the first support layer thereby forming an image sheet; laminating the image sheet to a clear plastic base, and removing the second support layer, forming a transparency.
The invention further involves a method for laminating a transparency consisting of the steps of: laminating a clear plastic base to a clear receiver sheet having a first thermal print layer and a first support layer; consisting of a first support base and first release layer, removing the first support layer forming a prelaminated construction; creating an imaged receiver sheet having an image, a thermal print layer, and the second support layer, consisting of a second support base, aluminized layer and second release layer. Laminating the pre-laminated construction with the imaged receiver sheet, thereby encapsulating the image; and removing the second support layer, forming a transparency.
The invention also relates to a method for laminating a transparency consisting of the steps of: creating an imaged receiver sheet having an image, a thermal print layer, and a support layer; consisting of a support base, aluminized layer and release layer, laminating a clear plastic base to the imaged receiver sheet; and removing the first support layer, forming a transparency.
Finally, the invention also relates to a method for proofing a transparency, consisting of the steps of: creating an imaged receiver sheet with an image, a first thermal print layer, a support layer; consisting of a support base, aluminized layer and first release layer; laminating a clear receiver sheet with a second thermal print layer, a clear support layer consisting of; a clear support base and second release layer with the imaged receiver sheet, thereby encapsulating the image; removing the first support layer forming a transparency; viewing the transparency for image quality; and if the image is acceptable to the user, laminating the transparency to a receiver stock, removing the clear support if desired, forming a pre-press proof.
The invention, and its objects and advantages, will become more apparent, in the detailed description of the preferred embodiments presented below.